Python Experimente iPython notebook

Python-Experimente.ipynb

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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Dynamischer Dispatch"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Der folgende Code zeigt, dass mit `getattr` nicht nur Werte sondern auch Methoden einer Klasse zur\u00fcckgeliefert und benutzt werden k\u00f6nnen."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class MyClass(object):\n",
      "\n",
      "    def test1(self):\n",
      "        print \"test 1\"\n",
      "\n",
      "    def test2(self):\n",
      "        print \"test 2\"\n",
      "\n",
      "        \n",
      "    def dispatch(self, testnumber):\n",
      "        method_name = \"test{:d}\".format(testnumber)\n",
      "        try:\n",
      "            getattr(self, method_name)()\n",
      "        except AttributeError:\n",
      "            print \"Methode '{:s}' nicht gefunden\".format(method_name)\n",
      "\n",
      "m = MyClass()\n",
      "\n",
      "t1 = getattr(m, \"test1\")\n",
      "print t1\n",
      "t1()\n",
      "\n",
      "m.dispatch(2)\n",
      "m.dispatch(3)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<bound method MyClass.test1 of <__main__.MyClass object at 0x3760b10>>\n",
        "test 1\n",
        "test 2\n",
        "Methode 'test3' nicht gefunden\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Typen"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "print type([])\n",
      "print type({})\n",
      "print type(\"\")\n",
      "print type(0)\n",
      "print type(0.0)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<type 'list'>\n",
        "<type 'dict'>\n",
        "<type 'str'>\n",
        "<type 'int'>\n",
        "<type 'float'>\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "List, Tuple und Dictionary Comprehensions"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "t = (\"a\", \"b\")\n",
      "l1 = [i.upper() for i in t]\n",
      "print l1\n",
      "d = {\"a\": \"foo\", \"b\": \"bar\", \"z\":\"baz\"}\n",
      "d2 = {k : v.upper() for (k,v) in d.iteritems() }\n",
      "print d2"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "['A', 'B']\n",
        "{'a': 'FOO', 'b': 'BAR', 'z': 'BAZ'}\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Flattening nested lists"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "l = [[1,2], [3,4], [5,6]]\n",
      "print [e for i in l for e in i]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[1, 2, 3, 4, 5, 6]\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Multiple return values"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Nesting multiple return values in a set or list is optional\n",
      "def ret1():\n",
      "    return (2,3)\n",
      "\n",
      "def ret2():\n",
      "    return 4,2\n",
      "\n",
      "def ret3():\n",
      "    return [47,11]\n",
      "\n",
      "v1,v2 = ret1()\n",
      "v3,v4 = ret2()\n",
      "v5,v6 = ret3()\n",
      "\n",
      "print [v1,v2,v3,v4,v5,v6]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[2, 3, 4, 2, 47, 11]\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Encoding Conversions"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "u1 = u\"\u00d6lk\u00fcmmel\"\n",
      "s1 = u1.encode(\"utf-8\") # Convert to str\n",
      "u2 = s1.decode(\"utf-8\") # Back to unicode\n",
      "# print as list to see internal representation\n",
      "print [u1,s1,u2]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[u'\\xd6lk\\xfcmmel', '\\xc3\\x96lk\\xc3\\xbcmmel', u'\\xd6lk\\xfcmmel']\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Test JSON encoding\n",
      "import json\n",
      "j1 = json.dumps(u1)\n",
      "j2 = json.dumps(s1)\n",
      "print json.dumps(j1)\n",
      "print json.dumps(j2)\n",
      "# print as list to see internal representation\n",
      "print [json.loads(j1), json.loads(j2)]\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\"\\\"\\\\u00d6lk\\\\u00fcmmel\\\"\"\n",
        "\"\\\"\\\\u00d6lk\\\\u00fcmmel\\\"\"\n",
        "[u'\\xd6lk\\xfcmmel', u'\\xd6lk\\xfcmmel']\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Test regular expression splitting\n",
      "import re\n",
      "splitted = re.split(\"k\", u1)\n",
      "print splitted"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[u'\\xd6l', u'\\xfcmmel']\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
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